1. Field of the Invention
The invention relates to an artificial sausage casing which is closed with a yarn having a metal insert. More specifically, the invention is characterized in that the metal insert improves the closed sausage casing with respect to increased safety on stuffing and processing after stuffing regarding the knot's slipping off the pleated end, so that the clip which is otherwise necessary can be omitted.
2. Brief Description of the Invention
Of interest here are tubular films which are used as enclosure of pasty foods or non-foods. They are generally offered as cut pieces closed at one end which is provided with a loop. Generally, the closure of the cut piece is at the same time made of the same material as the loop itself. The yarn for the loop can consist of highly varied materials. Illustratively, “Wursthüllen Kunstdarm” [Sausage casings, artificial sausage casing], 2nd Edition 1991 by Mr Gerhard Effenberger, pages 54 and 55, discloses yarns of cotton oriented polypropylene, polyamide or polyester and mixtures of various plastic types of material. The yarns can be used in the most varied constructions, e.g., braided, double, triple, six-fold or eight-fold twisted yarn or dyed, with or without a core.
As a variant for closing the cut piece, one can use clips which have been produced from aluminium or alloys thereof, which are individually shaped or have been produced from a wire during the process. Also useful for this application are plastic clips.
In the case of closing the cut piece with clips only, a loop must be further attached to suspend the sausage. This loop can be prefabricated or can be manufactured directly during the converting of the cut pieces. The yarn for the loop consists of the same materials as used for abovementioned loops.
Closure with a yarn is generally carried out using the ZD1 machine from VEB Verpackungsmaschinenbau Dresden, parent company of VEB Kombinat Nagema. The ZD1 machines, may contain, an automatic clipper which would enable a yarn closure with the corresponding loop and a clip closure, in one working operation.
DE-A-200 01 581 discloses a type of closure in which the end of a cut piece of an artificial sausage casing has been turned over in a region of 2 cm, pleated and closed with a yarn which connects to this turned over edge. Turning the skin over achieves a higher security against the knot slipping off.
In the abovementioned publication “Wursthüllen Kunstdarm” a yarn closure is described in which the end of a cut piece has been turned over in a larger region of 3 cm, pleated, and closed with a yarn which is mounted on this turned-over region. Incorporating the casing beneath the knot achieves still more security against the knot slipping off.
There are also ties used, which consist of a combination of yarn and the corresponding loop and an additional clip, which are both independently of one another mounted on the closed end of a tie. In this case, the yarn, with the loop, performs the closure of the cut piece of the artificial casing. The clip is placed behind the loop, that is to say between the end of the cut piece and the loop. The clip serves the following purpose: when applying a load to the loop, the knot can only slip up to the clip. (safety clip).
This clip closure is carried out in the above described ZD1 machines with a built-in automatic clipper, so that a closure of yarn with the corresponding loop and a clip closure can be produced in one working operation.
In certain countries, particular value is placed on the detectability of foreign bodies, such as metals, in the sausage. By means of the metal insert, the yarn can then be detected using corresponding detectors.
The yarn types listed have the disadvantage that they are elastic in a relatively large range. This is manifested in a knot always loosening slightly when knot is being tightened, and after the tightening force has been removed. Furthermore, when the cut piece of the artificial casing is being processed, the knot is stressed, so that loosening it can occur here also.
Before the casings are stuffed with sausage mix, they must usually be soaked for approximately 30 minutes, so that the sausage casing becomes sufficiently elastic for the stuffing process. The moisture absorption of the sausage casing causes, for example in the case of cellulose fibrous sausage casing, swelling, under the knot, so that an additional tension is built up on the knot. This tension causes an additional loosening of the knot. Also, the yarn itself, by the moisture absorption, undergoes a change in length and/or decreased mechanical properties, depending on the yarn type, which damages the stability of the knot.
After the cut pieces are stuffed, they are closed on the other side and the stuffed cut pieces are suspended on the loop on what are termed spits. On the transport racks, the suspended sausages are pushed into the cooking chamber and, in the case of scalded-emulsion and cooked-meat sausages, are customarily cooked at temperatures of approximately 70-90° C.
In addition, the temperature stress on cooking also leads to an expansion of the yarn and thus to a loss of strength.
The safe closure of cut pieces of sausages and safety against the knot slipping off during processing of the sausage creates a high demand for the type of closure. In particular, this is required in the case of long pieces, for example from lengths from 1.5 m or in general also in the case of large calibres (greater than calibre 75). In addition to high weight, frequently very high and pulsating stuffing pressures are used during the stuffing process. High demands of the reliability against the knot slipping off are also made in the case of sausage casings having a readily sliding or slippery surface. Examples which may be mentioned here are externally coated fibrous sausage casing types, lacquered textile sausage casings and plastic sausage casings. When these sausage casing types are printed with a full-surface printing with commercially conventional two-component colours, this demand further increases.
It was an object of the invention to choose a type of closure which withstands these high pulsating stuffing pressures and also is strong enough during the further processing of the stuffed sausage that the closure, during stuffing and further processing of the sausage, remains at the same point and thus offers sufficient safety against slipping off.